Implement a suggestion from Brett Viren: The TCanvas::Print("file.ps(") mechanism is very useful, but it can be a little inconvenient to have the action of opening/closing a file being atomic with printing a page.  Particularly if pages are being generated in some loop one needs to detect the special cases of first and last page and then munge the argument to Print() accordingly.
Implement a suggestion from Brett Viren:
The TCanvas::Print("file.ps(") mechanism is very useful, but it can be
a little inconvenient to have the action of opening/closing a file
being atomic with printing a page.  Particularly if pages are being
generated in some loop one needs to detect the special cases of first
and last page and then munge the argument to Print() accordingly.

To keep the API the same I'd think choosing a new hint, say "[" and
"]" would work.  Example:

  canvas->Print("file.ps[");   // No actual print, just open file.ps
  for (int i=0; i<10; ++i) {
    // fill canvas for context i
    // ...

    canvas->Print("file.ps");  // actually print canvas to file
  }// end loop
  canvas->Print("file.ps]");   // No actual print, just close.


git-svn-id: ecbadac9c76e8cf640a0bca86f6bd796c98521e3@6227 27541ba8-7e3a-0410-8455-c3a389f83636

dawehner/root,dawehner/root,dawehner/root,bbannier/ROOT,dawehner/root,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,bbannier/ROOT,dawehner/root,bbannier/ROOT,dawehner/root,bbannier/ROOT,dawehner/root,dawehner/root